"It’s with incredible shock and sadness that I’m letting our friends and family know that my amazing brother, Dave Goldberg, beloved husband of Sheryl Sandberg, father of two wonderful children, and son of Paula Goldberg, passed away suddenly last night," Robert Goldberg stated in a public post on Saturday morning. "No words can express the depth of loss we feel, but we want his children to learn how much he meant to all of you."

It’s with incredible shock and sadness that I’m letting our friends and family know that my amazing brother, Dave...

Sheryl Sandberg references her husband consistently throughout Lean In -- including on the first page.

"To my parents, for raising me to believe that anything was possible," she writes on the dedication page. "And to my husband, for making everything possible."

An entire chapter of the book was called "Make Your Partner a Real Partner," and elaborated on how her marriage to Dave made both parenthood and the corporate C-suite possible for Sheryl.

"Anyone who wants her mate to be a true partner must treat him as an equal -- and equally capable -- partner," Sandberg wrote. "I truly believe that the single most important career decision that a woman makes it whether she will have a life partner and who that partner is. … My career and marriage are inextricably intertwined."

Dave founded an online music site called Launch Media, which was acquired by Yahoo in 2001. He was the vice president of Yahoo Music when they married in 2004. When Sheryl was pregnant with their first child, she was living near Facebook HQ in the Bay Area, and Dave was in Los Angeles heading up his team at Yahoo. Eventually, he agreed to leave Yahoo and come to Silicon Valley to be with her full-time.

He joined the team at SurveyMonkey in 2009, and celebrated his sixth anniversary at the company in April.

"Having a true partner like Dave is still far too rare," Sheryl wrote in Lean In.

Dave Goldberg's Facebook profile has been turned into an official memorial page.